Synergistic Strong-Weak Adsorption Coupling in the FeN 6 –CoN 4 Dual-Site Modulates Oxygen Reduction Pathways via Oxygen Adsorbate Evolution-to-Dissociation Transition

Atomically dispersed non-noble metal–nitrogen-carbon electrocatalysts could derive a four-electron oxygen reduction reaction (ORR) described via a typical adsorbate evolution mechanism (AEM), but their kinetics are limited by the linear scaling relationship (LSR) between the *OOH and *OH. Herein, we reported heteronuclear dual-site FeN6–CoN4 materials obtained via integrating Fe3+ and Co2+ into pyrrole-functionalized g-C3N4 nanosheets. Such electrocatalysts broke the conventional LSR through a shifted oxygen dissociation mechanism (ODM: *O2 → *O + *OH → 2 *OH). Density functional theory calculations confirmed the strongest and weakest adsorption strengths of key ORR intermediates in the CoN4 and FeN6 sites with a conventional AEM pathway. Under the synergistic effect of dual-site strong-weak adsorption, FeN6–CoN4 switched from ORR pathways to the ODM observed via in situ infrared spectroscopy for the rate-determining step (*O2 → *O + *OH) with the decreased overpotentials of 0.41 V (FeN6) and 0.50 V (CoN4), enhancing intrinsic ORR kinetics. A Zn–air battery based on FeN6–CoN4 demonstrated an open-circuit voltage of 1.65 V approaching the theoretical 1.68 V, high-power density of 314 mW cm–2, and durable discharge at 500 mA cm–2. This work provides fundamental insights into dual-site synergy for regulating ORR pathways, offering a strategy for designing efficient atomic catalysts.